<input> elements with type="file" let the user choose one or more files from their device storage. Once chosen, the files can be uploaded to a server using form submission, or manipulated using JavaScript code and the File API.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Value

A file input's value attribute contains a DOMString that represents the path to the selected file(s). If the user selected multiple files, the value represents the first file in the list of files they selected. The other files can be identified using the input's HTMLInputElement.files property.

A Boolean which, if present, indicates that the user may choose more than one file

accept

A string that defines the file types the file input should accept. This string is a comma-separated list of unique file type specifiers. Because a given file type may be identified in more than one manner, it's useful to provide a thorough set of type specifiers when you need files of a given format.

For instance, there are a number of ways Microsoft Word files can be identified, so a site that accepts Word files might use an <input> like this:

capture

A string that specifies which camera to use for capture of image or video data, if the accept attribute indicates that the input should be of one of those types. A value of user indicates that the user-facing camera and/or microphone should be used. A value of environment specifies that the outward-facing camera and/or microphone should be used. If this attribute is missing, the user agent is free to decide on its own what to do. If the requested facing mode isn't available, the user agent may fall back to its preferred default mode.

Note:capture was previously a Boolean attribute which, if present, requested that the device's media capture device(s) such as camera or microphone be used instead of requesting a file input.

files

A FileList object that lists every selected file. This list has no more than one member unless the multiple attribute is specified.

multiple

When the multiple Boolean attribute is specified, the file input allows the user to select more than one file.

Non-standard attributes

In addition to the attributes listed above, the following non-standard attributes are available on some browsers. You should try to avoid using them when possible, since doing so will limit the ability of your code to function in browsers that don't implement them.

A Boolean indicating whether or not to only allow the user to choose a directory (or directories, if multiple is also present)

webkitdirectory

The Boolean webkitdirectory attribute, if present, indicates that only directories should be available to be selected by the user in the file picker interface. See HTMLInputElement.webkitdirectory for additional details and examples.

Note: Though originally implemented only for WebKit-based browsers, webkitdirectory is also usable in Microsoft Edge as well as Firefox 50 and later. However, even though it has relatively broad support, it is still not standard and should not be used unless you have no alternative.

Unique file type specifiers

A unique file type specifier is a string that describes a type of file that may be selected by the user in an <input> element of type file. Each unique file type specifier may take one of the following forms:

A valid case-insensitive filename extension, starting with a period (".") character. For example: .jpg, .pdf, or .doc.

A valid MIME type string, with no extensions.

The string audio/* meaning "any audio file".

The string video/* meaning "any video file".

The string image/* meaning "any image file".

The accept attribute takes as its value a string containing one or more of these unique file type specifiers, separated by commas. For example, a file picker that needs content that can be presented as an image, including both standard image formats and PDF files, might look like this:

Regardless of the user's device or operating system, the file input provides a button that opens up a file picker dialog that allows the user to choose a file.

Including the multiple attribute, as shown above, specifies that multiple files can be chosen at once. The user can choose multiple files from the file picker in any way that their chosen platform allows (e.g. by holding down Shift or Control, and then clicking). If you only want the user to choose a single file per <input>, omit the multiple attribute.

When the form is submitted, each selected file's name will be added to URL parameters in the following fashion: ?file=file1.txt&file=file2.txt

Getting information on selected files

The selected files' are returned by the element's HTMLInputElement.files property, which is a FileList object containing a list of File objects. The FileList behaves like an array, so you can check its length property to get the number of selected files.

Each File object contains the following information:

name

The file's name.

lastModified

A number specifying the date and time at which the file was last modified, in milliseconds since the UNIX epoch (January 1, 1970 at midnight).

lastModifiedDate

A Date object representing the date and time at which the file was last modified. This is deprecated and should not be used. Use lastModified instead.

A string specifying the file's path relative to the base directory selected in a directory picker (that is, a file picker in which the webkitdirectory attribute is set). This is non-standard and should be used with caution.

Note: You can set as well as get the value of HTMLInputElement.files in all modern browsers; this was most recently added to Firefox, in version 57 (see bug 1384030).

Limiting accepted file types

Often you won't want the user to be able to pick any arbitrary type of file; instead, you often want them to select files of a specific type or types. For example, if your file input lets users upload a profile picture, you probably want them to select web-compatible image formats, such as JPEG or PNG.

Acceptable file types can be specified with the accept attribute, which takes a comma-separated list of allowed file extensions or MIME types. Some examples:

It may look similar, but if you try selecting a file with this input, you'll see that the file picker only lets you select the file types specified in the accept value (the exact nature differs across browsers and operating systems).

The accept attribute doesn't validate the types of the selected files; it simply provides hints for browsers to guide users towards selecting the correct file types. It is still possible (in most cases) for users to toggle an option in the file chooser that makes it possible to override this and select any file they wish, and then choose incorrect file types.

Because of this, you should make sure that the accept attribute is backed up by appropriate server-side validation.

Examples

In this example, we'll present a slightly more advanced file chooser that takes advantage of the file information available in the HTMLInputElement.files property, as well as showing off a few clever tricks.

Note: You can see the complete source code for this example on GitHub — file-example.html (see it live also). We won't explain the CSS; the JavaScript is the main focus.

This is similar to what we've seen before — nothing special to comment on.

Next, let's walk through the JavaScript.

In the first lines of script, we get references to the form input itself, and the <div> element with the class of .preview. Next, we hide the <input> element — we do this because file inputs tend to be ugly, difficult to style, and inconsistent in their design across browsers. You can activate the input element by clicking its <label>, so it is better to visually hide the input and style the label like a button, so the user will know to interact with it if they want to upload files.

Note:opacity is used to hide the file input instead of visibility: hidden or display: none, because assistive technology interprets the latter two styles to mean the file input isn't interactive.

Next, we add an event listener to the input to listen for changes to its selected value changes (in this case, when files are selected). The event listener invokes our custom updateImageDisplay() function.

Grab the FileList object that contains the information on all the selected files, and store it in a variable called curFiles.

Check to see if no files were selected, by checking if curFiles.length is equal to 0. If so, print a message into the preview <div> stating that no files have been selected.

If files have been selected, we loop through each one, printing information about it into the preview <div>. Things to note here:

We use the custom validFileType() function to check whether the file is of the correct type (e.g. the image types specified in the accept attribute).

If it is, we:

Print out its name and file size into a list item inside the previous <div> (obtained from curFiles[i].name and curFiles[i].size). The custom returnFileSize() function returns a nicely-formatted version of the size in bytes/KB/MB (by default the browser reports the size in absolute bytes).

Generate a thumbnail preview of the image by calling window.URL.createObjectURL(curFiles[i]) and reducing the image size in the CSS, then insert that image into the list item too.

If the file type is invalid, we display a message inside a list item telling the user that they need to select a different file type.

The custom validFileType() function takes a File object as a parameter, then loops through the list of allowed file types, checking if any matches the file's type property. If a match is found, the function returns true. If no match is found, it returns false.